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Ohms Law Low-current Calibration System for Ionization Chambers
Published
Author(s)
Dean G. Jarrett, Shamith U. Payagala, Ryan P. Fitzgerald, Denis E. Bergeron, Jeffrey T. Cessna, Charles J. Waduwarage Perera, Neil M. Zimmerman
Abstract
A system for the calibration of electrometers that measure currents from ionization chambers is described. The calibration system uses a 1 GΩ standard resistor in series with a stable voltage source to generate calibration currents from 1 pA to 20 nA, traceable to quantum voltage and resistance standards through an 8-1/2 digit digital voltmeter and the standard resistor. Expanded uncertainties (k = 2) of 100 x 10-6 or better for the calibration of the electrometer is needed for the ionization chamber measurements. The electrometer calibration was verified by current measurements following the decay of the short-lived radionuclide 18F in a re-entrant ionization chamber.
Proceedings Title
2020 Conference on Precision Electromagnetic Measurements(CPEM 2020)
Conference Dates
August 24-28, 2020
Conference Location
Denver, CO
Pub Type
Conferences
Keywords
electrometer, ionization chamber, quantum electrical standards, standard resistor, small current measurement
Jarrett, D.
, Payagala, S.
, Fitzgerald, R.
, Bergeron, D.
, Cessna, J.
, Waduwarage, C.
and Zimmerman, N.
(2020),
Ohms Law Low-current Calibration System for Ionization Chambers, 2020 Conference on Precision Electromagnetic Measurements(CPEM 2020), Denver, CO
(Accessed October 10, 2025)